<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../js/react.development.js"></script>
    <script src="../js/react-dom.development.js"></script>
    <script src="../js/babel.min.js"></script>
</head>
<body>
    <div id="root"></div>
    <script type="text/babel">
        let aList = ['a', 'b'];

        let e1= = aList.map(function (item, i) {
            return <li key={i}>{item}</li>
        });

        ReactDOM.render(
            <ul>{e1}</ul>,
            document.getElementById('root')
        )
    </script>
</body>
</html>